Diabetic Men May Soon Be Able to Grow Their Own Insulin-Making Cells

Men with type-1 diabetes might be able to grow new insulin cells from their own testicular tissue, according to a new study. Testicular treatment could even be safer and more effective than stem-cell therapies.

Researchers at Georgetown University Medical Center were able to coax human spermatogonial stem cells, which are precursors to sperm cells, into becoming adult stem cells. Sperm cells already have the genes necessary to become embryonic stem cells, the researchers point out in a Georgetown news release. This way, the researchers didn’t have to use gene therapy to create induced pluripotent stem cells (IPS cells) — “These are true, pluripotent stem cells,” said G. Ian Gallicano, an associate professor in the Department of Cell Biology and Director of the Transgenic Core Facility at GUMC.

The team took one gram of tissue from human testes from deceased organ donors and produced about one million stem cells in the lab. The cells showed many of the biological markers that characterize normal beta islet cells, which are insulin-secreting cells normally found in the pancreas. Then the team transplanted the cells into diabetic mice, and were able to decrease the animals’ glucose levels.

The proof-of-concept study could yield a new, safer treatment for type 1 diabetes, also called juvenile diabetes. Current treatments include transplanting islet cells from deceased donors, but this can result in rejection, and there are only so many donors. Researchers have cured diabetes in mice using IPS cells, but these can produce tumors as well as problems stemming from the external genes used to create IPS cells, according to Gallicano. The new method bypasses IPS cells, because sperm cells are already a form of stem cells. The study was reported Sunday at the American Society of Cell Biology 50th annual meeting in Philadelphia.